Automatic stop.



V. H. CARMAN.

AUTOMATIC STOP.

APPLICATION TILED AUG.4,1913.

Patented Feb. 16, 1915.

WITNESSES.

ATIORIVEV UNITED STATES PATENT omen.

VICTOR H. CABHAN, OI INDIANAPOLIS, INDIANA, ASSIGNOB TO Cm & ram ACOPABTNERSHIP COMPOSED OF VICTOR H. CA BMAN AND DAVID L. FRY

AUTOMATIC STOP.

Specification of Letters Yatent.

. Patented Feb. 16, 1915.

Application filed August 4, 1913. Serial No. 782,817.

useful Automatic Stop, of which the following is a specification.

In the operation of certain moving devices, such as some electricswitches, it is desirable that the device in its movement in onedirection be stopped for a time in an intermediate position between theinitial position and the linal position. Such is the case, for instance,in the star-delta switch shown in my prior Patent No. 1,009,061, issuedAugusta, 1913.

It is the object of my present invention to provide automatic means forpositively producing such stopping, especially in such star-deltaswitch.

The accompanying drawing illustratesinv invention as applied to theaforesaid stardelta switch. I

Figure 1 is a perspective view showing such a star-delta switch equippedwith my invention, the switch being shown open in fulllines andcompletely closed, in position for delta connection, in dotted lines:Figs. '2, 3, and 4 are detail views showing the operation of thestopping means in successive positions of the switch in its movement:Fig. 5 is a section on the line 5.' of Fig. 2; Fig. 6 is a section onthe line 6-43 of Fig. 3; and Figs. 7 and S are diagrams showing theconnections produced by the stardelta switch in its intermediateposition and in its full closed position, respectively.

In my aforesaid star-delta switch, there is an insulating base 10 onwhich are mounted a plurality of pivotal supports 11. 12, and 13, towhich are pivoted the switch blades 14, 15, and 1G. The outer end ofthe-e switch blades are suitably fastened to an insulating cross bar 17.whereby they may be moved together by a common operarbing handle 18. Theknife blades cooperate with two sets of contacts 19. .20, and 21. and'22. .23. and ll. each of which contacts has the two spring leaves usualin knife switch contacts. The contacts 19, 20, and 21 a re longer thanthe contacts '22, :2 and 24. so that they are engaged first by therespective knife blades as the latter are swung downwardly but remain inengagement with the knife blades after the latter engage the contacts'22, Q3, and 24. The contacts 22, 23, and 2% are provided with auxiliarycontacts 23' and 23", and 2*, respectively, these auxiliary contacts,-which are conveniently though not necessarily separate pieces from themain contacts, extending upward and toward the auxiliary contacts of theadjacent main contacts, as shown in Fig. 1, 50

that auxiliary switch blade contacts 25 and 3 carried by insulatingblocks 21' and 22S suitably ifnounted on the cross bar 17. may passbetween and engage the contacts 2;! and 23', and :23" and 24respectively, when the switch has been brought to its first closed (orintermediate) position, in which the switch blades respectively engagethe contacts 19, 20, and ".21. as stated above. The contacts 12'. .20,and 21 are connected to the corresponding ends (the clockwise ends asillustrated) of Coils 30-. I31, and 23;, spectively; and the contacts'32., 23, and it are connected to the other (or counterclockwise) endsof coils 231, 212. and 25". respectively. Thus the two ends of each ofsaid coils are connected to .non-corrcs louding contacts of the two setsof contacts. The coils 5H. :31, and 32 are illustrated as the primarywindings of a three-phase induction motor 7- 1. but may be any othercoils which it is desired to control in a similar inauncr.

\Vhen the switch above described is open (or 111 its initial position).the coils 30, 31, and t are entirely disconnected. 'hen the switch ismoved to its tirst"cl'osed (or intermediate) position, the switch bladesll. 15, and 11' engage the contacts 1 9. '10, and :1. respectively. andthe auxiliary switch blade contacts 25 and 2H engage the auxiliarycontacts 2;! and 2 3. and 23" and :21. respectivcly, thus connecting thethree windings 30, Sl, and 3; in star to the three-phase sup ply mains33. 3!), and 37. When the switch is moved to its full closed (or Iinal)posi tion. the switch blades ll. 15. and 1" engage the contacts 19 and22. i and 2 3. and 21 and 24. respectively. and the auxiliary switchblade contacts 3-3 and 26 pass out of engagement with. and theinsulating blocks '17 and '28 pass between. the. auxiliary con tacts.thus breaking the star connection and connecting the three windings 3U.31, and 32 to the supply mains in delta. This switch SllO.il(l beallowed to remain for a time in its intermediate position. to maintainthe star connection while the motor,

gains speed. In order to insure this, my

pres'ent. invention, provides an automatic stop which positively stopsthe switch in its intermediate position as it is moved'from open to fullclosed position. To this end one of the set of contacts first engaged bythe knife blades, say the contact 20, is provided near the top with atransverse opening'40 projecting through both leaves of the contact, anda stop 'pin 41 is carried by a leaf spring 42 so that it may move intosuch opening to block the path of the switch blade 15 or -out'of suchopening to leave such path clear, the two positions being shown in Figs.6 and 5 respectively. The pin 41 is preferably arranged so that when itis engaged on top by theswitch blade 15, as'shown in Fig. 6, the leafspring 42 will yield sufficiently so that the'under side of the pin willbe. supported by the'lowe'r parts of the opening 40, thereby relievingthe strain on the leaf spring. This'leaf spring, which is convenientlyfastened between the bottom of the contact 20' and the base 10,

normally stands in thelposition shown in Fig. 5, leaving the path clearbetween 'the two leaves of the contact 20. In order to movethe leafspring 42 and the pin 41 to the other or stopping position, the knifeblade has attachedto its side an operating plate 43, which cooperateswith the upper end' of the spring 42. As the switch is moved .from opentoward full closed position, and is approaching its intermediateposition, an oblique finger 44 on the plate first engages afinger at the:top of the leaf spring 42, as shown in Fig. 2, and by a cam actionforces the spring 42 toward the contact 20. As the switch bladescontinue their downward movement, the finger 45 asses smoothly fromengagement with the i1 er 44 into engagement with the inclined main wall46 of the plate 43, and is forced thereby farther toward the contact 20.The

uppereedge of the main wall 46 is the closest to the switchf'blade 1.5,at a suflicien't distance therefrom to allow room for a leaf of thecontact 20 and the leaf spring 42. The pin 41 now fully occupies theopening 40. As the switch blade continues downward, the'wall 46passesout of engagement with the finger 45, but engages a lower finger47 on the spring 42, momentarily allowing the leaf spring 42 to springout very slightly from the contact 20 so that the upper edge of the wallprojects through a notch 48 between the fingers 45 and 47 to the innerside of the finger ,45; but this outward springing is not sufficient toallow the pin41 to clear the path for the knife blade 15 between the twoleaves of the contact 20.v The switch is now in the position shown inThe notch 48 is sufiiciently narrow so that the projecting pointed endof the wall 46 covers the finger 47 before it passes out of engagementwith the finger 45. In

switch positively about this position of the switch, or very slightlythereafter, the switch blade 15 engages the upper surface of the pin 41and is positively stopped thereby from continuing downward toward itsfinal closed position, the wall 46 engaging the finger 47 to holdthe'leaf spring 42 so closely against the contact 20 that the pin 41fully occupies theopening 40. The windings 30, 31, and 32 are nowconnected in star. When it is the desire to move the switch beyond theinter mediate position to the full closed position, it is first movedslightly toward open position, in which movement the end of the inclinedwall 46 passes through the notch 48 to the space between the finger 45and the I are ready to serve their purpose to stop the in intermediateposition upon the next closing. of the switch.

I claim as my invention 2-- 1. A switch comprising a pivoted knifeblade, ardouble leaf contact which said knife blade engages as theswitch is moved toward closed position, a second contact which the knifeblade engages .after 'it engages the first contact, said first contactbeing provided with a transverse opening, a pin'movable into and out ofsuch opening, and means carried by the switch blade for movingvsaid pininto said opening to block the path of the switchblade after the latterhas been moved into engagement with the first contact but before it hasmoved into engagement with the second contact.

2. A switch comprising a pivoted 'knife blade, a double leaf contactwhich said knife blade engages as the switch is moved toward closedposition, a second contact which the knife blade engages after itengages the first contact, said first contact being provided with atransverse opening, a pin movable into and out of such'opening, andmeans carried by the switch blade for moying said pin into said openingto block the path of .ions, a sto movable into and out of the path ofsaici movable switch member to stop it in its intermediate position, andmeans carried by said switch member for moving said stop into stoppingposition as the switch member approaches its intermediate position fromits open position and holding said stop in said stopping position untilthe switch member has been stopped in such intermediate position.

4. In combination, a movable switch member having open, intermediate,and final positions, a stop movable into and out of the path of saidswitch member itself to stop it in its intermediate position, and meanscarried by said switch member for moving said stop into stoppingposition as the switch member approaches its intermediate position fromits open position, said stop being spring mounted, and said meanscarried by t e switch member requiring said switch member to be movedslightly backward from its intermediate position in order to allow saidstop to spring out of the path of the switch member, thereby allowingthe switch member to be moved through the intermediate position to thefinal position.

5. In a knife switch, the combination of a pivoted knife blade havingopen, intermediate, and final positions, and means controlled by themovement of the switch blade from open position toward final positionfor positively stopping it in its intermediate position.

6. In a knife switch, the combination of a pivoted knife blade havingopen. intermediate. and final positions, and means controlled by themovement of the switch blade from open position toward final positionfor positively stopping it in its intermediate position and forermitting the knife blade to move on to nal position after a preliminaryslight backward movement from intermediate position.

7. In ijOITlbllltlClOIl. a member movable in a definite path and havinginitial. intermediate, and final positions. a spring-mounted stopnormally out of such path. and means carried by said member for movingsaid stop into the path of said member positively to stop the latter inintermediate position as it is moved from initial position toward finalposition said means requiring a preliminary slight backward movement ofthe member from intermediate position in order to permit said stop tospring out of such path to allow the member to continue its movementfrom intermediate position to final position.

8. In combination, a member movable in a definite path and havinginitial, intermediate, and final positions, a stop normally out of suchpath, and means carried by said member for moving said stop into the athof said member positively to stop the atter in intermediate position asit is moved from initial position toward final position and for holdingsaid stop in the path of said member until said member has been stoppedin intermediate position.

9. In combination, a switch member having initial, intermediate. andfinal positions, a stop movable into and out of the path of said switchmember to stop it in its intermediate position as it is moved frominitial position toward final position, and means carried by said switchmember for moving said stop into stopping position as the switch memberapproaches its intermediate position from its initial position and forholding said stop in stopping position until the switch member is movedbackward slightly from intermediate position after having reached suchposition.

10. In combination. a member movable in a definite path and havinginitial, intermediate, and final positions, a stop normally out of suchpath, and means carried by said member for moving said stop into suchpath to stop said member in intermediate position as it is moved frominitial position toward final position and for holding said stop in suchpath to prevent movement of said member beyond intermediate positionuntil said member is moved slightly backward from its intermediateposition after having reached such position.

11. A switch comprising a pivoted knife blade. :1 double leaf contactwith which said knife blade engages as the switch is moved toward closedposition. a second contact which the knife blade engages after itengages the first contact. said first contact being provided with atransverse opening, a pin movable into and out of such opening in suchclose proximity to that wall thereof which is toward the closed positionof the switch that such pin will be forced against such wall when thepin is engaged by the switch blade. and means carried by the switchblade for moving said pin into such opening to block the path of suchblade after the latter has been moved into engagement with the firstcontact but before it has been brought into engagement with the secondcontact.

In witness whereof. I have hereunto set my hand at Indianapolis.Indiana, this second day of August. A. D. one thousand nine hundred andthirteen.

VICTOR H. CARMAN.

Witnesses:

Lou'isr. Bmmm'r, G. B. SCHLEY.

